Rack mechanism for automatic dishwasher



July 2, 1968 c. A. PETERSON RACK MECHANISM FOR AUTOMATIC DISHWASHERFiledDec. 14, 1966 V '4 FIG. I.

3e fr-22 mveufon L h l/B BYCurl A. Peterson United States Patent3,390,930 RACK MECHANISM FOR AUTOMATIC DISHWASHER Carl A. Peterson,Columbus, Ohio, assignor to Westinghouse Electric Corporation,Pittsburgh, Pa., 21 corporation of Pennsylvania Filed Dec. 14, 1966,Ser. No. 601,713 4 Claims. (Cl. 312269) ABSTRACT OF THE DISCLOSURE Adomestic portable dishwasher is provided with a top dish rack sectioncomprising separate front and rear racks, each pivotally suspended bylinkages from the hinged lid for the elevation up out of the tub todifferent levels when the lid is opened. The bottom dish rack is alsoconnected to the linkages so that it rises within the tub inaccordancewith the elevation of the top rack section.

This invention relates generally to dishwashers and in particular to atop opening dishwasher provided with a dish rack arrangement adapted tofacilitate loading and unloading of the dishes.

Some current top opening dishwashers are provided with a split top racksection in which the separate front top rack is linked to the lid of thedishwasher to be moved up and out of the way when the lid is opened.This arrangement permits the use of a top rack section which issubstantially co-extensive with the interior tub area on a horizontalplane and which affords reasonably good access to the lower rack sectionwhen the lid is raised. In such arrangements, so far as I know, theentire lower rack remains stationary when the lid is raised.

This invention deals with a dishwasher having a rack arrangement inwhich access for loading and unloading of the dishes is furtherimproved. In accordance with the invention, both the separate front andrear racks of the top section are linked to the lid for elevation up outof the tub when the lid is raised, and the lower rack is also elevatedwithin the tub to a higher position when the lid is opened. Thus, incontrast with the prior art arrangement of elevating the front, or thefront and rear racks of the top section, with my arrangement accordingto the invention in its preferred form all portions of the racks areelevated. Further, in accordance with the invention, the linkage is suchthat it tends to promote stability of the racks during their movementeven though the linkage is of essentially simple character.

The invention will be described in more detail in connection with theaccompanying drawing illustrating a preferred embodiment by way ofexample, and wherein:

FIGURE 1 is a partly broken side view of a dishwasher provided with arack arrangement according to the invention, and with the lid in aclosed position;

FIG. 2 is a partly broken side view of the dishwasher with its lid fullyopened; and

IG. 3 is a horizontal sectional view corresponding to one taken alongthe line I-II--III of FIG. 1.

Referring to the drawing, the dishwasher illustrated is of the portable,wheel supported character. Its basic housing structure includes an outershell which is generally rectangular in horizontal cross-section, aninner tub 12 also of generally rectangular cross-section nested withinthe shell, and a top lid 14 pivoted about its rear edge at 16 formovement from a closed position as shown in FIG. 1, to an open positionas shown in FIG. 2. It is noted that certain conventional parts of thedishwasher are omitted, and other parts not directly concerned with theinventive arrangement are shown merely by way of example. Thecounterbalance means for the lid may be of 3,390,933 Patented July 2,1968 the nature disclosed in US. Patent 3,001,227, for example, or takeother forms which provide suflicient force holding the lid in an openposition for loading. Any of numerous water distribution systems may beprovided for the interior of the dishwasher. One suitable arrangement asshown in FIG. 1 may include a rotatable lower arm 18 through which apart of the water is discharged against the lower rack, and a conduit 20for guiding the rest of thewater to a spinner 22 which disperses ittoward the upper rack.

The top dish rack section according to the invention comprises aseparate rear rack 24 and a separate front rack 26. Each may be of anopen-work coated wire construction, and together they are substantiallycoextensive with the horizontal cross-sectional area of the upper por-,

tion of the tub except for clearance spaces as required for the movementof the racks.

Both racks 24 and 26 are supported from the lid for elevational andpivotal movement in accordance with movement of the lid. To this end, alid rear arm 28 is secured to depend down from the undersurface of thelid at each side of the tub. The lower end of each rear arm is pivotallyconnected to the side frame of the rack 24 at a generally centeredlocation 30 of the side area of the rack to establish a pivotal axisparallel to the axis of the lid hinge.

The front rack 26 is similarly suspended for pivotal and elevationalmovement with the lid from somewhat longer depending arms 32 havingtheir lower ends pivotally connected at 34 to the side frames adjacentthe bottom of the rack. Both the lid rear arms 28, and the lid frontarms 32, have their upper ends rigidly fixed to the undersurface of thelid so that the generally right angle relationship between the arms andthe lid is maintained in all positions of the lid.

The single bottom dish rack 36 is also of generally open-work wireconstruction and encompasses a horizontal area which is generallycoextensive with the horizontal inside area of the tub. The lower rackis suspended for substantially translational vertical movement with thetub in accordance with movement of the lid and the upper section. Whilevarious mean-s may be provided to guide the lower rack in this movement,the means currently contemplated include vertical guide means near therear of the rack, and a spring suspension system at the front of therack.

The vertical guide means may include a pair of vertically disposed,inwardly open, channel-shaped tracks 38 scoured to the side inner faceat each side of the tub, with each track 38 receiving a pair ofvertically spaced wheels 40 and 42 securedone above each other to eachside of the bottom rack. One or more tension springs 44, having upperends connected to the tub front wall and lower ends connected to thefront of the rack, may be provided when the guide tracks and wheels areprovided near the rear of the rack. Transmission of the force forlifting the lower rack, and controlling its descent, in accordance withthe lid movement, is through a lifting link 46 at each side of the tub.The lifting link may comprise a downward extension of the rear rack 24side frame with a bottom pivotal connection 48 to the bottom rack sideframe.

The final linkage in the system is a stabilizing link 50 at each sideconnecting the front lower corner of the top front rack 26 to thelifting link 46. Both end connections are pivotal at 52 and 54. Thislink exerts a stabilizing force preventing the front top rack 26 fromtipping and invertmg.

The following further explains and summarizes the functions, advantagesand interrelationships of the component parts of the rack and linkagesystem.

Due to the front rack 26 being pivotally suspended from longer arms onan axis to its bottom, and the rear rack 24 being pivotally suspendedfrom shorter arms on a higher axis, both racks occupy substantially thesame level in the upper portion of the tub with the lid closed, but arespaced apart substantially with the lid open. The provision of thelifting link 46 as a rigidly connected part of the rear rack frame, withits lower end confined, enhances the stability of the rear rack. Thestabilizing link 50 ties the front rack movement to the rear linkagesystem and controls the tilting of the front rack 26 during movement.Thus, the linkage system is designed so that the various parts cooperatewith each other through the linkages to exert forces which result in thedesired movements and positioning.

The provision of the guide wheels 40 and 42 one above the other aids inholding the lower rack 36 in a horizontal disposition, and the tensionspring 44 (selected in accordance with the average load which the lowerrack will contain) helps support the front end of the lower rack whetherloaded or not. Finally, the rear rack being shorter in a front-to-reardirection than the front rack gives greater open area above the elevatedlower rack for inserting and removing dishes, when the lid is open, thanif the racks were of equal size.

I claim as my invention: 1. In a top opening dishwasher of the typehaving a lid pivoted along its rear edge for selectively closing anupwardly open washing tub:

a top dish rack section in said tub including a separate front dishrack, and a separate rear dish rack;

front and rear arms depending from said lid in a closed position intosaid tub for pivotally suspending the front and rear racks,respectively, therefrom, the upper ends of said depending arms beingfixed to said lid;

a bottom raclc in said tub;

means for guiding said bottom rack for vertical movement;

means connecting said bottom rack to said rear rack arm means forvertical movement of said bottom rack in accordance with movement ofsaid top rack section with said lid, and

said rear rack is substantially narrower in a front-torear directionthan said top rack so that the front face of said rear rack is recessedappreciably from the front face of said front rack when said lid isfully opened, to provide a greater access opening to said bottom rackthan if said front and rear racks were of substantially thesamedimension in a frontto-rear direction.

2. In a dishwasher according to claim 1 wherein:

said guiding means for said bottom rack includes vertical track means onopposite sides of said bottom rack, and roller means connected to saidbottom rack received by said track means; and

said track means is generally aligned vertically with the location ofsaid pivotal suspension of said rear track with said depending rear armin both a lid closed and a lid open position.

3. In a dishwasher according to claim 2:

means located adjacent the front of said bottom rack for urging saidbottom rack in an upward direction.

4. In a top opening dishwasher of the type having a lid pivoted alongits rear edge for selectively closing an upwardly open washing tub;

a top dish rack section in said tub including a separate front dishrack, and a separate rear dish rack;

front and rear arms depending from said lid in a closed position intosaid tub for pivotally suspending the front and rear racks,respectively, therefrom, the upper ends of said depending arms beingfixed to said lid;

a bottom rack in said tub;

said rear rack being substantially narrower in a frontto-rear directionthan said top rack so that the front face of said rear rack is recessedappreciably from the front face of said front rack when said lid isfully open, to provide a greater access opening to said bottom rack thanif said front and rear racks were of substantially the same dimension ina front-torear direction.

References Cited UNITED STATES PATENTS 1,479,236 1/1924 Heidbrink312-269 X 1,652,984 12/1927 Hixson 312-269 X 3,087,769 4/1963 Guth312-269 3,195,969 7/1965 Wallen 312-269 3,310,354 3/1967 Pattison312-269 3,321,261 5/1967 Guth 312-269 3,322,479 5/ 1967 Payton et al312-269 JAMES T. McCALL, Primary Examiner.

